There are 4 parathyroid glands in the neck and they are responsible for the production of parathyroid hormone which maintains calcium homeostasis throughout the body. They are difficult to identify relative to the other tissues in the neck such s lymph nodes, fat, thyroid etc. This has resulted in the incidence of accidental parathyroid removal ranging from 8% to 19% of patients undergoing total thyroidectomy. Damage to the parathyroid gland(s) can cause hypoparathyroidism and hypocalcemia resulting in serious and deleterious side effects. There are 3 different surgery procedures in the neck region where a key part of surgery protocol is for the surgeon to visually identify the parathyroid clearly to avod accidental injury and removal. These are Thyroidectomy (involving partial or complete removal of thyroid), Parathyroidectomy (involving removal of one or more parathyroid glands) and modified Neck Dissection (involving removal of lymph nodes in neck into which cancer has spread). In a recent discovery, the PI Prof. Mahadevan-Jansen's group at Vanderbilt University reported for the first time the breakthrough finding that the Parathyroid Gland has a unique autofluorescence signature in the NIR under illumination at 785nm. The Phase 1 research demonstrated a prototype platform based on this technology that could do point detection and imaging. The specific aims of this proposal is to build upon that work and it seeks to a) Develop a product that can function in two modes: A point detection mode that can be used to confirm if a candidate tissue is parathyroid or not An imaging mode that can be used to look at a region to guide the surgeon to then using the point detection mode to confirm b) To investigate the use of the auto-fluorescence technology to assess lymph nodes intra-operatively for cancer metastases. c) To detect parathyroid vascularization via diffuse reflectance spectroscopy